1. Field of the Invention
The present invention relates to methods of treating a wastewater stream produced from hydrocarbon production operations for repurposing as a disinfectant used in hydrocarbon production operations.
2. Background Information
Aqueous treatment fluids may be used in a variety of subterranean treatments. Such treatments include, but are not limited to, drilling operations, stimulation operations, and completion operations. As used herein, the term “treatment,” or “treating,” refers to any subterranean operation that uses a fluid in conjunction with a desired function and/or for a desired purpose. The term “treatment,” or “treating,” does not imply any particular action by the fluid.
One example of a treatment fluid are viscous gelled fracturing fluids commonly utilized in the hydraulic fracturing of subterranean zones penetrated by well bores to increase the production of hydrocarbons from the subterranean zones. That is, a viscous fracturing fluid is pumped through the well bore into a subterranean zone to be stimulated at a rate and pressure such that fractures are formed and extended into the subterranean zone. The fracturing fluid also carries particulate proppant material, e.g., graded sand, into the formed fractures. The proppant material is suspended in the viscous fracturing fluid so that the proppant material is deposited in the fractures when the viscous fracturing fluid is broken and recovered. The proppant material functions to prevent the fractures from closing whereby conductive channels are formed through which produced fluids can flow to the well bore.
An example of a stimulation operation utilizing an aqueous treatment fluid is hydraulic fracturing. In some instances, a fracturing treatment involves pumping a proppant-free, aqueous treatment fluid (known as a pad fluid) into a subterranean formation faster than the fluid can escape into the formation so that the pressure in the formation rises and the formation breaks, creating or enhancing one or more fractures. Enhancing a fracture includes enlarging a pre-existing fracture in the formation. Once the fracture is formed or enhanced, proppant particulates are generally placed into the fracture to form a proppant pack that may prevent the fracture from closing when the hydraulic pressure is released, forming conductive channels through which fluids may flow to the well bore.
In many cases, soluble salts from down-hole formations dissolve into the fluids used in the hydraulic fracturing process and are returned to the surface in the form of produced and flowback waters. These waters are considered wastewaters that are typically disposed of through chemical or thermal treatment or injection into disposal wells. However, due to government regulation and the volume of wastewater produced, it is becoming more difficult to properly dispose of wastewater resulting from hydrocarbon production operations.
There is a need in the art to provide alternative uses for the wastewater resulting from hydrocarbon production operations in order to avoid the need to dispose of it.